 
(* ::Section:: *)
(* GenericPropagatorDenominator *)
(* ::Text:: *)
(*GenericPropagatorDenominator[expr, {n, s}]  is a generic factor of the denominator of a propagator. Unlike PropagatorDenominator that is supposed to mean 1/(q^2-m^2), expr in GenericPropagatorDenominator can be an arbitrary combination of Pair, CartesianPair and TemporalPair objects. Using n one can specify the power of the propagator, while s (+1 or -1) fixes the sign of  I*eta. GenericPropagatorDenominator is an internal object. To enter such propagators in FeynCalc you should use GFAD.*)


(* ::Subsection:: *)
(* Examples *)
FeynAmpDenominator[GenericPropagatorDenominator[x,{1,1}]]

FeynAmpDenominator[GenericPropagatorDenominator[2 z Pair[Momentum[p1,D],Momentum[Q,D]]Pair[Momentum[p2,D],Momentum[Q,D]]-Pair[Momentum[p1,D],Momentum[p2,D]],{1,1}]]
